To qualify, please please publish your work (or publish a post linking to it) on the Effective Altruism Forum, the AI Alignment Forum, or LessWrong with a “Future Fund worldview prize” tag. You can also participate in the contest by publishing your submission somewhere else (e.g. arXiv or your blog) and filling out this submission form. We will then linkpost/crosspost to your submission on the EA Forum.
But it is not possible to tag the post with “Future Fund worldview prize”. It seems to me that only existing tags can be used.
I think there was a tag, but it might have gotten deleted. I made a new one — you should be able to use it now.